Biosphere 2 Set for Big Indoor Weather Test

Photo: A recent view shows the interior of Biosphere 2. Credit: Hbarrison via Wikimedia Commons Remember Biosphere 2, the glass-enclosed Arizona facility built in the early 1990s that contained man-made replicas of deserts and rainforests, and was designed to test how well humans could survive within closed, artificial ecosystems?

That much-hyped mission is long over, but today, under management of the University of Arizona, the Biosphere has a new role as a laboratory for scientists who want to study natural processes in a controlled environment.

One such important experiment will start in July, in what New Scientist touts as the world's largest indoor weather experiment. They plan to make it rain inside the biosphere and then study how the water moves through a landscape.

According to New Scientist, the experiment features three artificial hills inside the facility, which weigh roughly 1.1 million pounds apiece and are fashioned from crushed basalt, a volcanic rock. Every three days, the scientists will cause rain to fall equally on all three hills, which are equipped with more than 1,800 embedded sensors to measure everything from water content to carbon dioxide levels.

The scientists plan to mix isotope-labelled molecules of hydrogen, lithium bromide and lithium chloride into the artificial rain, which will enable them to track individual molecules in more detail than ever before.

The experiment will look not just at water movement, but also at the minerals and nutrients that water picks up as it flows though rocks and soil. That process, called weathering, is crucial to the existence of life in ecosystems, from microbes to plants and animals, and can determine how productive farm fields may be and also the ways in which a landscape changes over time.

One of the researchers, geomorphologist Jean Dixon from Montana State University in Bozeman, Mont., explained to New Scientist that .the calcium, potassium and magnesium in our diets originally came from rocks.

"Chemical weathering is the first thing you need in order to form a habitable planet," she said.